Examine the effects of canal preparation and filling on the incidence of dentinal defects
N = 80
Extracted mandibular premolars were divided equally in four groups. Group 1 was left unprepared. All other root canals were prepared using Gates Glidden drills and System GT files up to size-40, 0.06 taper at the working length. Group 2 was not filled while the canals of the other groups were filled with gutta-percha and AH26, either with a master cone and passive insertion of secondary gutta percha points (group 3) or lateral compaction (group 4). Roots were then sectioned horizontally 3, 6, and 9 mm from the apex and observed under a microscope. The presence of dentinal defects (fractures, craze lines or incomplete cracks) was noted and the differences between the groups were analyzed with the Fisher’s exact test.
Canal preparation alone created significantly more defects than unprepared canals (P < 0.05). The total number of defects after lateral compaction was significantly larger than after non-compaction canal filling.
Root canal preparation and filling of extracted teeth created dentine defects such as fractures, craze lines and incomplete cracks